by any chance, when you are running Studio 4, In Ryzen Master are there any RED indicators at the top?
If there are, that means the processor is probably throttling which would impact your performance.
Check the Processor's temps when under heavy loads.
EDIT: Went to Studio 4 website and it has a Answer & Question on how to prevent high CPU Usage and Optimize Windows 10 for Audio: Managing CPU usage in Studio One and overcoming high CPU problems on your system. – Knowledge Base |...
Mentions how to increase Performance by the CPU.
If you already read this in the past, I apologize then.